Key result
Intrinsic and extrinsic factors control actomyosin organization in zebrafish cardiomyocytes to promote curvature morphogenesis.
Why the study?
The cellular and molecular mechanisms underlying the formation of cardiac chamber curvatures remain poorly understood.
Intrinsic and extrinsic factors intersect to control actomyosin organization in outer curvature cardiomyocytes, promoting cell shape changes during cardiac chamber morphogenesis.
Should not change clinical practice; leaves open translation to mammalian cardiac morphogenesis.
Cardiac chambers emerge from a heart tube that balloons and bends to create expanded ventricular and atrial structures, each containing a convex outer curvature (OC) and a recessed inner curvature (IC). The cellular and molecular mechanisms underlying the formation of these characteristic curvatures remain poorly understood. Here, we demonstrate in zebrafish that the initially similar populations of OC and IC ventricular cardiomyocytes diverge in the organization of their actomyosin cytoskeleton and subsequently acquire distinct OC and IC cell shapes. Altering actomyosin dynamics hinders cell shape changes in the OC, and mosaic analyses indicate that actomyosin regulates cardiomyocyte shape in a cell-autonomous manner. Additionally, both biomechanical cues and the transcription factor Tbx5a influence the basal enrichment of actomyosin and squamous cell morphologies in the OC. Together, our findings demonstrate that intrinsic and extrinsic factors intersect to control actomyosin organization in OC cardiomyocytes, which in turn promotes the cell shape changes that accompany curvature morphogenesis.
No takes yet. Share an insight, caveat, or question.
Leerberg et al. (2025) studied Cardiac chamber curvature formation. In zebrafish, intrinsic and extrinsic factors intersect to control actomyosin organization in outer curvature cardiomyocytes, promoting cell shape changes that accompany curvature morphogenesis.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: